Afoil is a character who contrasts another character to highlight certain things about them
Both Banquo and Macbeth are captains in the army referred to by Duncan as "our captains Macbeth and Banquo" in Act 1, Scene 2
Both are brave warriors as explained by the sergeant in the same scene
Duncan refers to Banquo as noble in Act 1, Scene 4
Following meeting the witches in Act 1, Scene 3, Macbeth receives three prophecies including becoming king, while Banquo receives a prophecy that his descendants will be kings
Banquo is skeptical and wary of the witches' prophecies
Banquo does not succumb to the prophecies in the same way as Macbeth due to not having the same ambition or fatal flaw
Shakespeare alters Banquo's character from his source material to paint him in a more positive light
Banquo's resistance to evil and his goodness ultimately cost him his life
Banquo's wisdom and good nature are acknowledged by Macbeth in Act 3, Scene 1
Banquo's character complements Macbeth by highlighting Macbeth's downfall
Banquo is a more complex character than he may seem, with actions and indecision that paint him as neither all good nor all evil